Biodiesel is an alternative diesel fuel derived from vegetable oils or animal fats. The transesterification of an oil or a fat with an alcohol (usually methanol but in some cases longer chain alcohols) yields fatty acid methyl esters (FAMEs), known as biodiesel.
Although biodiesel can be used by itself, it is also blended with traditional diesel fuel bases to form biodiesel blends. However, the addition of biodiesel in relatively high portions to the diesel fuel base results in a blend with poor cold flow properties. In cold climates such fuels can result in diesel injector nozzle blockage with particulates, mainly wax crystals. This places restrictions on the amount and type of fatty acid methyl ester (FAME) that can be added to biodiesel blends. This is especially true for fatty acid methyl esters that are predominantly saturated. Cold filter plugging point (CFPP) additives are used to improve CFPP, however such additives do not perform well in the presence of FAME's and blends thereof.
It is an object of this invention to address this problem.